Thickness

canvas.nodes([1, 2, 3, 4, 5, 6]).add()
canvas.edges([[1, 3], [1, 6], [2, 3], [2, 4],
    [3, 4], [3, 5], [4, 5], [5, 6]]).add()

canvas.pause(0.5)
const spanningTree = [[1, 6], [5, 6], [3, 5], [2, 3], [2, 4]]
canvas.edges(spanningTree).thickness(6).color('pink')